As humans, we must face the uncomfortable reality that we are guilty of wasting food. The age old adage of our eyes being bigger than our stomach often rings true, leaving us with uneaten parts of our lunchtime sandwich, partially consumed fruit, or dinner leftovers that sit in the fridge destined for the garbage can on trash night. Food waste isn’t a simple problem to solve, and we have yet to devise any broadly applied solutions, such as a food waste recycling program. However, scientists working in the bioenergy field have made exciting progress turning food waste into renewable energy, with a breakthrough recently unveiled by Sarah Na, a senior and proud Korean-American in AGNR’s Department of Environmental Science and Technology.
Under the tutelage of AGNR’s Stephanie Lansing, a renowned bioenergy expert, Na discovered that when fed into a biodigester—a system that biologically digests organic material with the goal of producing biogas—fermented food waste creates almost double the amount of biogas as non-fermented food waste. Fermented food waste can be understood as a product that has already been through the microbial process and is partially broken down. There are more intermediate compounds like volatile fatty acids in fermented food waste vs. raw food waste that can be converted into biogas. This finding has major implications for renewable gas/energy production for powering things like cars, and a myriad of household appliances.
It can also be used to generate electricity and to produce fertilizer for home and commercial use.
“Before starting this experiment, I thought the biogas output for fermented foods would be lower, but I was pleasantly surprised to see that it was actually a lot more than I anticipated,” said Na. “It’s exciting that I was able to be on the frontlines of this discovery.”
Sarah never intended to work in the bioenergy field as part of her undergraduate studies, but became intrigued after a stint as a summer intern under Lansing as part of AGNR’s Summer Opportunities in Agricultural Research and the Environment (SOARE) program.
“Through this research, I’m hoping that the public will understand that food waste is not simply waste, that you can take it and repurpose it for a variety of different uses,” said Na. “As a society, we can take waste products and do something with them to help further the benefits of a circular economy.”
by Graham Binder : Momentum Winter 2023
